#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>

int main()
{
	char s[20];
	char* p;

	printf("please input string:\n");
	scanf("%s", s);
	p = s;

	while (*p != '\0')
	{
		if (*p >= 'A' && *p <= 'Z')
			*p = *p + 'a' - 'A';
		p++;
	}

	p = s;

	while (*p != '\0')
	{
		putchar(*p);
		p++;
	}

	printf("\n");

	return 0;
}